1. Field of the Invention
The present invention relates to a golf club head having a face portion that has optimized compliance and contributes to optimized ball speed robustness.
2. Description of the Related Art
Technical innovation in the material, construction and performance of golf clubs has resulted in a variety of new products. The advent of metals as a structural material has largely replaced natural wood for wood-type golf club heads, and is but one example of this technical innovation resulting in a major change in the golf industry. In conjunction with such major changes are smaller scale refinements to likewise achieve dramatic results in golf club performance. For example, the metals comprising the structural elements of a golf club head have distinct requirements according to location in the golf club head. A sole or bottom section of the golf club head should be capable of withstanding high frictional forces for contacting the ground. A crown or top section should be lightweight to maintain a low center of gravity. A front or face of the golf club head should exhibit high strength and durability to withstand repeated impact with a golf ball. While various metals and composites are known for use in the face, several problems arise from the use of homogeneous and non-homogeneous face materials.
A non-homogeneous face structure typically involves an insert centrally located which requires an exacting fit between two or more distinct elements, but has the advantage of utilizing beneficial material properties in a combination which is not available in each material individually. A homogeneous face structure is simpler to manufacture but is limited to the inherent material properties of one material. The present invention enhances the performance advantages of both homogenous and non-homogeneous face structures by implementing a simple structural change.
The Rules of Golf, established and interpreted by the United States Golf Association (“USGA”) and The Royal and Ancient Golf Club of Saint Andrews, set forth certain requirements for a golf club head. The requirements for a golf club head are found in Rule 4 and Appendix II. Complete descriptions of the Rules of Golf are available on the USGA web page at www.usga.org. Although the Rules of Golf do not expressly state specific parameters for a golf club face, Rule 4-1e prohibits the face from having the effect at impact of a spring with a golf ball. In 1998, the USGA adopted a test procedure pursuant to Rule 4-1e, which measures club face COR. This USGA test procedure, as well as procedures like it, may be used to measure club face COR.